// SPDX-License-Identifier: GPL-2.0-only
/*
 * Core Source for:
 * Cypress TrueTouch(TM) Standard Product (TTSP) touchscreen drivers.
 * For use with Cypress Txx3xx parts.
 * Supported parts include:
 * CY8CTST341
 * CY8CTMA340
 *
 * Copyright (C) 2009, 2010, 2011 Cypress Semiconductor, Inc.
 * Copyright (C) 2012 Javier Martinez Canillas <javier@dowhile0.org>
 *
 * Contact Cypress Semiconductor at www.cypress.com <kev@cypress.com>
 */

#include <linux/delay.h>
#include <linux/export.h>
#include <linux/input.h>
#include <linux/input/mt.h>
#include <linux/input/touchscreen.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/property.h>
#include <linux/gpio/consumer.h>
#include <linux/regulator/consumer.h>

#include "cyttsp_core.h"

/* Bootloader number of command keys */
#define CY_NUM_BL_KEYS          8

/* helpers */
#define GET_NUM_TOUCHES(x)              ((x) & 0x0F)
#define IS_LARGE_AREA(x)                (((x) & 0x10) >> 4)
#define IS_BAD_PKT(x)                   ((x) & 0x20)
#define IS_VALID_APP(x)                 ((x) & 0x01)
#define IS_OPERATIONAL_ERR(x)           ((x) & 0x3F)
#define GET_HSTMODE(reg)                (((reg) & 0x70) >> 4)
#define GET_BOOTLOADERMODE(reg)         (((reg) & 0x10) >> 4)

#define CY_REG_BASE                     0x00
#define CY_REG_ACT_DIST                 0x1E
#define CY_REG_ACT_INTRVL               0x1D
#define CY_REG_TCH_TMOUT                (CY_REG_ACT_INTRVL + 1)
#define CY_REG_LP_INTRVL                (CY_REG_TCH_TMOUT + 1)
#define CY_MAXZ                         255
#define CY_DELAY_DFLT                   20 /* ms */
#define CY_DELAY_MAX                    500
/* Active distance in pixels for a gesture to be reported */
#define CY_ACT_DIST_DFLT                0xF8 /* pixels */
#define CY_ACT_DIST_MASK                0x0F
/* Active Power state scanning/processing refresh interval */
#define CY_ACT_INTRVL_DFLT              0x00 /* ms */
/* Low Power state scanning/processing refresh interval */
#define CY_LP_INTRVL_DFLT               0x0A /* ms */
/* touch timeout for the Active power */
#define CY_TCH_TMOUT_DFLT               0xFF /* ms */
#define CY_HNDSHK_BIT                   0x80
/* device mode bits */
#define CY_OPERATE_MODE                 0x00
#define CY_SYSINFO_MODE                 0x10
/* power mode select bits */
#define CY_SOFT_RESET_MODE              0x01 /* return to Bootloader mode */
#define CY_DEEP_SLEEP_MODE              0x02
#define CY_LOW_POWER_MODE               0x04

/* Slots management */
#define CY_MAX_FINGER                   4
#define CY_MAX_ID                       16

static const u8 bl_command[] = {
        0x00,                   /* file offset */
        0xFF,                   /* command */
        0xA5,                   /* exit bootloader command */
        0, 1, 2, 3, 4, 5, 6, 7  /* default keys */
};

static int ttsp_read_block_data(struct cyttsp *ts, u8 command,
                                u8 length, void *buf)
{
        int error;
        int tries;

        for (tries = 0; tries < CY_NUM_RETRY; tries++) {
                error = ts->bus_ops->read(ts->dev, ts->xfer_buf, command,
                                length, buf);
                if (!error)
                        return 0;

                msleep(CY_DELAY_DFLT);
        }

        return -EIO;
}

static int ttsp_write_block_data(struct cyttsp *ts, u8 command,
                                 u8 length, void *buf)
{
        int error;
        int tries;

        for (tries = 0; tries < CY_NUM_RETRY; tries++) {
                error = ts->bus_ops->write(ts->dev, ts->xfer_buf, command,
                                length, buf);
                if (!error)
                        return 0;

                msleep(CY_DELAY_DFLT);
        }

        return -EIO;
}

static int ttsp_send_command(struct cyttsp *ts, u8 cmd)
{
        return ttsp_write_block_data(ts, CY_REG_BASE, sizeof(cmd), &cmd);
}

static int cyttsp_handshake(struct cyttsp *ts)
{
        if (ts->use_hndshk)
                return ttsp_send_command(ts,
                                ts->xy_data.hst_mode ^ CY_HNDSHK_BIT);

        return 0;
}

static int cyttsp_load_bl_regs(struct cyttsp *ts)
{
        memset(&ts->bl_data, 0, sizeof(ts->bl_data));
        ts->bl_data.bl_status = 0x10;

        return ttsp_read_block_data(ts, CY_REG_BASE,
                                    sizeof(ts->bl_data), &ts->bl_data);
}

static int cyttsp_exit_bl_mode(struct cyttsp *ts)
{
        int error;
        u8 bl_cmd[sizeof(bl_command)];

        memcpy(bl_cmd, bl_command, sizeof(bl_command));
        if (ts->bl_keys)
                memcpy(&bl_cmd[sizeof(bl_command) - CY_NUM_BL_KEYS],
                        ts->bl_keys, CY_NUM_BL_KEYS);

        error = ttsp_write_block_data(ts, CY_REG_BASE,
                                      sizeof(bl_cmd), bl_cmd);
        if (error)
                return error;

        /* wait for TTSP Device to complete the operation */
        msleep(CY_DELAY_DFLT);

        error = cyttsp_load_bl_regs(ts);
        if (error)
                return error;

        if (GET_BOOTLOADERMODE(ts->bl_data.bl_status))
                return -EIO;

        return 0;
}

static int cyttsp_set_operational_mode(struct cyttsp *ts)
{
        int error;

        error = ttsp_send_command(ts, CY_OPERATE_MODE);
        if (error)
                return error;

        /* wait for TTSP Device to complete switch to Operational mode */
        error = ttsp_read_block_data(ts, CY_REG_BASE,
                                     sizeof(ts->xy_data), &ts->xy_data);
        if (error)
                return error;

        error = cyttsp_handshake(ts);
        if (error)
                return error;

        return ts->xy_data.act_dist == CY_ACT_DIST_DFLT ? -EIO : 0;
}

static int cyttsp_set_sysinfo_mode(struct cyttsp *ts)
{
        int error;

        memset(&ts->sysinfo_data, 0, sizeof(ts->sysinfo_data));

        /* switch to sysinfo mode */
        error = ttsp_send_command(ts, CY_SYSINFO_MODE);
        if (error)
                return error;

        /* read sysinfo registers */
        msleep(CY_DELAY_DFLT);
        error = ttsp_read_block_data(ts, CY_REG_BASE, sizeof(ts->sysinfo_data),
                                      &ts->sysinfo_data);
        if (error)
                return error;

        error = cyttsp_handshake(ts);
        if (error)
                return error;

        if (!ts->sysinfo_data.tts_verh && !ts->sysinfo_data.tts_verl)
                return -EIO;

        return 0;
}

static int cyttsp_set_sysinfo_regs(struct cyttsp *ts)
{
        int retval = 0;

        if (ts->act_intrvl != CY_ACT_INTRVL_DFLT ||
            ts->tch_tmout != CY_TCH_TMOUT_DFLT ||
            ts->lp_intrvl != CY_LP_INTRVL_DFLT) {

                u8 intrvl_ray[] = {
                        ts->act_intrvl,
                        ts->tch_tmout,
                        ts->lp_intrvl
                };

                /* set intrvl registers */
                retval = ttsp_write_block_data(ts, CY_REG_ACT_INTRVL,
                                        sizeof(intrvl_ray), intrvl_ray);
                msleep(CY_DELAY_DFLT);
        }

        return retval;
}

static void cyttsp_hard_reset(struct cyttsp *ts)
{
        if (ts->reset_gpio) {
                /*
                 * According to the CY8CTMA340 datasheet page 21, the external
                 * reset pulse width should be >= 1 ms. The datasheet does not
                 * specify how long we have to wait after reset but a vendor
                 * tree specifies 5 ms here.
                 */
                gpiod_set_value_cansleep(ts->reset_gpio, 1);
                usleep_range(1000, 2000);
                gpiod_set_value_cansleep(ts->reset_gpio, 0);
                usleep_range(5000, 6000);
        }
}

static int cyttsp_soft_reset(struct cyttsp *ts)
{
        int retval;

        /* wait for interrupt to set ready completion */
        reinit_completion(&ts->bl_ready);
        ts->state = CY_BL_STATE;

        enable_irq(ts->irq);

        retval = ttsp_send_command(ts, CY_SOFT_RESET_MODE);
        if (retval) {
                dev_err(ts->dev, "failed to send soft reset\n");
                goto out;
        }

        if (!wait_for_completion_timeout(&ts->bl_ready,
                        msecs_to_jiffies(CY_DELAY_DFLT * CY_DELAY_MAX))) {
                dev_err(ts->dev, "timeout waiting for soft reset\n");
                retval = -EIO;
        }

out:
        ts->state = CY_IDLE_STATE;
        disable_irq(ts->irq);
        return retval;
}

static int cyttsp_act_dist_setup(struct cyttsp *ts)
{
        u8 act_dist_setup = ts->act_dist;

        /* Init gesture; active distance setup */
        return ttsp_write_block_data(ts, CY_REG_ACT_DIST,
                                sizeof(act_dist_setup), &act_dist_setup);
}

static void cyttsp_extract_track_ids(struct cyttsp_xydata *xy_data, int *ids)
{
        ids[0] = xy_data->touch12_id >> 4;
        ids[1] = xy_data->touch12_id & 0xF;
        ids[2] = xy_data->touch34_id >> 4;
        ids[3] = xy_data->touch34_id & 0xF;
}

static const struct cyttsp_tch *cyttsp_get_tch(struct cyttsp_xydata *xy_data,
                                               int idx)
{
        switch (idx) {
        case 0:
                return &xy_data->tch1;
        case 1:
                return &xy_data->tch2;
        case 2:
                return &xy_data->tch3;
        case 3:
                return &xy_data->tch4;
        default:
                return NULL;
        }
}

static void cyttsp_report_tchdata(struct cyttsp *ts)
{
        struct cyttsp_xydata *xy_data = &ts->xy_data;
        struct input_dev *input = ts->input;
        int num_tch = GET_NUM_TOUCHES(xy_data->tt_stat);
        const struct cyttsp_tch *tch;
        int ids[CY_MAX_ID];
        int i;
        DECLARE_BITMAP(used, CY_MAX_ID);

        if (IS_LARGE_AREA(xy_data->tt_stat) == 1) {
                /* terminate all active tracks */
                num_tch = 0;
                dev_dbg(ts->dev, "%s: Large area detected\n", __func__);
        } else if (num_tch > CY_MAX_FINGER) {
                /* terminate all active tracks */
                num_tch = 0;
                dev_dbg(ts->dev, "%s: Num touch error detected\n", __func__);
        } else if (IS_BAD_PKT(xy_data->tt_mode)) {
                /* terminate all active tracks */
                num_tch = 0;
                dev_dbg(ts->dev, "%s: Invalid buffer detected\n", __func__);
        }

        cyttsp_extract_track_ids(xy_data, ids);

        bitmap_zero(used, CY_MAX_ID);

        for (i = 0; i < num_tch; i++) {
                tch = cyttsp_get_tch(xy_data, i);

                input_mt_slot(input, ids[i]);
                input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
                input_report_abs(input, ABS_MT_POSITION_X, be16_to_cpu(tch->x));
                input_report_abs(input, ABS_MT_POSITION_Y, be16_to_cpu(tch->y));
                input_report_abs(input, ABS_MT_TOUCH_MAJOR, tch->z);

                __set_bit(ids[i], used);
        }

        for (i = 0; i < CY_MAX_ID; i++) {
                if (test_bit(i, used))
                        continue;

                input_mt_slot(input, i);
                input_mt_report_slot_inactive(input);
        }

        input_sync(input);
}

static irqreturn_t cyttsp_irq(int irq, void *handle)
{
        struct cyttsp *ts = handle;
        int error;

        if (unlikely(ts->state == CY_BL_STATE)) {
                complete(&ts->bl_ready);
                goto out;
        }

        /* Get touch data from CYTTSP device */
        error = ttsp_read_block_data(ts, CY_REG_BASE,
                                 sizeof(struct cyttsp_xydata), &ts->xy_data);
        if (error)
                goto out;

        /* provide flow control handshake */
        error = cyttsp_handshake(ts);
        if (error)
                goto out;

        if (unlikely(ts->state == CY_IDLE_STATE))
                goto out;

        if (GET_BOOTLOADERMODE(ts->xy_data.tt_mode)) {
                /*
                 * TTSP device has reset back to bootloader mode.
                 * Restore to operational mode.
                 */
                error = cyttsp_exit_bl_mode(ts);
                if (error) {
                        dev_err(ts->dev,
                                "Could not return to operational mode, err: %d\n",
                                error);
                        ts->state = CY_IDLE_STATE;
                }
        } else {
                cyttsp_report_tchdata(ts);
        }

out:
        return IRQ_HANDLED;
}

static int cyttsp_power_on(struct cyttsp *ts)
{
        int error;

        error = cyttsp_soft_reset(ts);
        if (error)
                return error;

        error = cyttsp_load_bl_regs(ts);
        if (error)
                return error;

        if (GET_BOOTLOADERMODE(ts->bl_data.bl_status) &&
            IS_VALID_APP(ts->bl_data.bl_status)) {
                error = cyttsp_exit_bl_mode(ts);
                if (error) {
                        dev_err(ts->dev, "failed to exit bootloader mode\n");
                        return error;
                }
        }

        if (GET_HSTMODE(ts->bl_data.bl_file) != CY_OPERATE_MODE ||
            IS_OPERATIONAL_ERR(ts->bl_data.bl_status)) {
                return -ENODEV;
        }

        error = cyttsp_set_sysinfo_mode(ts);
        if (error)
                return error;

        error = cyttsp_set_sysinfo_regs(ts);
        if (error)
                return error;

        error = cyttsp_set_operational_mode(ts);
        if (error)
                return error;

        /* init active distance */
        error = cyttsp_act_dist_setup(ts);
        if (error)
                return error;

        ts->state = CY_ACTIVE_STATE;

        return 0;
}

static int cyttsp_enable(struct cyttsp *ts)
{
        int error;

        /*
         * The device firmware can wake on an I2C or SPI memory slave
         * address match. So just reading a register is sufficient to
         * wake up the device. The first read attempt will fail but it
         * will wake it up making the second read attempt successful.
         */
        error = ttsp_read_block_data(ts, CY_REG_BASE,
                                     sizeof(ts->xy_data), &ts->xy_data);
        if (error)
                return error;

        if (GET_HSTMODE(ts->xy_data.hst_mode))
                return -EIO;

        enable_irq(ts->irq);

        return 0;
}

static int cyttsp_disable(struct cyttsp *ts)
{
        int error;

        error = ttsp_send_command(ts, CY_LOW_POWER_MODE);
        if (error)
                return error;

        disable_irq(ts->irq);

        return 0;
}

static int cyttsp_suspend(struct device *dev)
{
        struct cyttsp *ts = dev_get_drvdata(dev);
        int retval = 0;

        mutex_lock(&ts->input->mutex);

        if (input_device_enabled(ts->input)) {
                retval = cyttsp_disable(ts);
                if (retval == 0)
                        ts->suspended = true;
        }

        mutex_unlock(&ts->input->mutex);

        return retval;
}

static int cyttsp_resume(struct device *dev)
{
        struct cyttsp *ts = dev_get_drvdata(dev);

        mutex_lock(&ts->input->mutex);

        if (input_device_enabled(ts->input))
                cyttsp_enable(ts);

        ts->suspended = false;

        mutex_unlock(&ts->input->mutex);

        return 0;
}

EXPORT_GPL_SIMPLE_DEV_PM_OPS(cyttsp_pm_ops, cyttsp_suspend, cyttsp_resume);

static int cyttsp_open(struct input_dev *dev)
{
        struct cyttsp *ts = input_get_drvdata(dev);
        int retval = 0;

        if (!ts->suspended)
                retval = cyttsp_enable(ts);

        return retval;
}

static void cyttsp_close(struct input_dev *dev)
{
        struct cyttsp *ts = input_get_drvdata(dev);

        if (!ts->suspended)
                cyttsp_disable(ts);
}

static int cyttsp_parse_properties(struct cyttsp *ts)
{
        struct device *dev = ts->dev;
        u32 dt_value;
        int ret;

        ts->bl_keys = devm_kzalloc(dev, CY_NUM_BL_KEYS, GFP_KERNEL);
        if (!ts->bl_keys)
                return -ENOMEM;

        /* Set some default values */
        ts->use_hndshk = false;
        ts->act_dist = CY_ACT_DIST_DFLT;
        ts->act_intrvl = CY_ACT_INTRVL_DFLT;
        ts->tch_tmout = CY_TCH_TMOUT_DFLT;
        ts->lp_intrvl = CY_LP_INTRVL_DFLT;

        ret = device_property_read_u8_array(dev, "bootloader-key",
                                            ts->bl_keys, CY_NUM_BL_KEYS);
        if (ret) {
                dev_err(dev,
                        "bootloader-key property could not be retrieved\n");
                return ret;
        }

        ts->use_hndshk = device_property_present(dev, "use-handshake");

        if (!device_property_read_u32(dev, "active-distance", &dt_value)) {
                if (dt_value > 15) {
                        dev_err(dev, "active-distance (%u) must be [0-15]\n",
                                dt_value);
                        return -EINVAL;
                }
                ts->act_dist &= ~CY_ACT_DIST_MASK;
                ts->act_dist |= dt_value;
        }

        if (!device_property_read_u32(dev, "active-interval-ms", &dt_value)) {
                if (dt_value > 255) {
                        dev_err(dev, "active-interval-ms (%u) must be [0-255]\n",
                                dt_value);
                        return -EINVAL;
                }
                ts->act_intrvl = dt_value;
        }

        if (!device_property_read_u32(dev, "lowpower-interval-ms", &dt_value)) {
                if (dt_value > 2550) {
                        dev_err(dev, "lowpower-interval-ms (%u) must be [0-2550]\n",
                                dt_value);
                        return -EINVAL;
                }
                /* Register value is expressed in 0.01s / bit */
                ts->lp_intrvl = dt_value / 10;
        }

        if (!device_property_read_u32(dev, "touch-timeout-ms", &dt_value)) {
                if (dt_value > 2550) {
                        dev_err(dev, "touch-timeout-ms (%u) must be [0-2550]\n",
                                dt_value);
                        return -EINVAL;
                }
                /* Register value is expressed in 0.01s / bit */
                ts->tch_tmout = dt_value / 10;
        }

        return 0;
}

struct cyttsp *cyttsp_probe(const struct cyttsp_bus_ops *bus_ops,
                            struct device *dev, int irq, size_t xfer_buf_size)
{
        /*
         * VCPIN is the analog voltage supply
         * VDD is the digital voltage supply
         */
        static const char * const supplies[] = { "vcpin", "vdd" };
        struct cyttsp *ts;
        struct input_dev *input_dev;
        int error;

        ts = devm_kzalloc(dev, sizeof(*ts) + xfer_buf_size, GFP_KERNEL);
        if (!ts)
                return ERR_PTR(-ENOMEM);

        input_dev = devm_input_allocate_device(dev);
        if (!input_dev)
                return ERR_PTR(-ENOMEM);

        ts->dev = dev;
        ts->input = input_dev;
        ts->bus_ops = bus_ops;
        ts->irq = irq;

        error = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(supplies),
                                               supplies);
        if (error) {
                dev_err(dev, "Failed to enable regulators: %d\n", error);
                return ERR_PTR(error);
        }

        ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
        if (IS_ERR(ts->reset_gpio)) {
                error = PTR_ERR(ts->reset_gpio);
                dev_err(dev, "Failed to request reset gpio, error %d\n", error);
                return ERR_PTR(error);
        }

        error = cyttsp_parse_properties(ts);
        if (error)
                return ERR_PTR(error);

        init_completion(&ts->bl_ready);

        input_dev->name = "Cypress TTSP TouchScreen";
        input_dev->id.bustype = bus_ops->bustype;
        input_dev->dev.parent = ts->dev;

        input_dev->open = cyttsp_open;
        input_dev->close = cyttsp_close;

        input_set_drvdata(input_dev, ts);

        input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_X);
        input_set_capability(input_dev, EV_ABS, ABS_MT_POSITION_Y);
        /* One byte for width 0..255 so this is the limit */
        input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);

        touchscreen_parse_properties(input_dev, true, NULL);

        error = input_mt_init_slots(input_dev, CY_MAX_ID, INPUT_MT_DIRECT);
        if (error) {
                dev_err(dev, "Unable to init MT slots.\n");
                return ERR_PTR(error);
        }

        error = devm_request_threaded_irq(dev, ts->irq, NULL, cyttsp_irq,
                                          IRQF_ONESHOT | IRQF_NO_AUTOEN,
                                          "cyttsp", ts);
        if (error) {
                dev_err(ts->dev, "failed to request IRQ %d, err: %d\n",
                        ts->irq, error);
                return ERR_PTR(error);
        }

        cyttsp_hard_reset(ts);

        error = cyttsp_power_on(ts);
        if (error)
                return ERR_PTR(error);

        error = input_register_device(input_dev);
        if (error) {
                dev_err(ts->dev, "failed to register input device: %d\n",
                        error);
                return ERR_PTR(error);
        }

        return ts;
}
EXPORT_SYMBOL_GPL(cyttsp_probe);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Cypress TrueTouch(R) Standard touchscreen driver core");
MODULE_AUTHOR("Cypress");